2015: A scanning Odyssey - Nikon Super Coolscan LS-9000 ED

Actually, it's "annus mirabilis" when it's just used to refer to a year of miracles in the nominative case, as "That was my annus mirabilis." "Anno" is commonly seen, but it's usually a mistake. It's the dative or ablative case of "annus", and would be rendered typically as to or in the or ayear. So in your original reference, where you did say "in that anno mirable [sic]...", you did have the anno right, if not the mirabilis.